P0A43
Drive Motor A Position Sensor Circuit Intermittent.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- A
- AreaHybrid propulsion
- 43
- FaultThe specific fault in that area
What it means
P0A43 is a generic powertrain code for hybrid and electric vehicles. It means the control unit has detected an intermittent fault in the circuit of the drive motor 'A' position sensor, which reports rotor angle and speed. The signal drops out, spikes or becomes implausible from time to time, rather than failing constantly.
Symptoms
- Malfunction indicator or hybrid system warning light on, which may come and go
- Intermittent loss of power or reduced power mode
- Car refuses to enter Ready mode or cuts out while driving
- Rough, jerky or hesitant acceleration from low speed
- Fault appears only over bumps, when hot or after washing the car
Possible causes
- Loose, corroded or damaged connector at the motor position sensor (resolver) or at the inverterlikely
- Chafed, stretched or broken wiring in the sensor harness, often near a flexing point or sharp edgelikely
- Moisture or coolant or oil contamination in the sensor connector or wiringpossible
- Electrical interference from damaged shielding or poor earth connections on the sensor circuitpossible
- Failing drive motor position sensor, with faults that depend on temperature or vibrationpossible
- Fault within the inverter or motor control unit's sensor interfacerare
How to diagnose
- Read all stored codes and freeze frame data to see speed, temperature and conditions when the fault set, and note any other motor or inverter codes.
- Check for relevant manufacturer service bulletins or software updates for your model, as the sensor layout and procedure vary by vehicle.
- Follow the manufacturer's high-voltage safety procedure before touching any orange high-voltage components; the sensor circuit is low voltage, but access often is not.
- Inspect the sensor harness and connectors for damage, chafing, corrosion, bent pins, water ingress and poor terminal tension.
- With the system safely powered, wiggle-test the harness while watching live position sensor data for dropouts or jumps.
- Check the sensor circuit's resistance, continuity and shorts to earth or voltage against the manufacturer's specification, with the connectors unplugged.
- Check the shielding and earth connections of the sensor circuit for integrity.
- If wiring checks out, test the sensor itself against the manufacturer's values, and only then consider the control unit.
How to fix
- Repair or replace damaged wiring sections and use the correct sealed connections.
- Clean, dry and reseat corroded connectors, or replace the connector or terminals if damaged, and seal against moisture.
- Restore damaged shielding or earth connections on the sensor circuit.
- Replace the drive motor position sensor if it fails testing, following the manufacturer's procedure and any required calibration or relearn.
- Apply a software update or repair the control unit only if a known fault is confirmed by the manufacturer's information.
Can I keep driving?
Medium severity
The car may be driven carefully for a short distance if it runs normally, but it can drop into reduced power or shut down without warning. Get it checked soon, and avoid driving if power loss is frequent or the car will not stay in Ready mode.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.